Fan-blower.



E. MULBAN.

' PAN BLOWER. APPLICATION FILED JULY 10, 1907.

1,556,811. 3 v Patented Mar. 25, 1913,

EMBURY MQLEAN, OF NEW YORK, N. Y.

teasers.

FAN-BLOWER.

Specification of Letters Patent. Patented )Iill. 25, 151 13 Application filed July 10, 1907. Serial No. 383,063.

which the following is a specification.

This invention relates to fan blowers and has particular application to a type of blower combining and embracing certain advantageous features of a volume blower and a pressure blower. 1

As is well known, there are two general types of fan blowers, namely, volume blowers and pressure blowers. The general distinction between the two types is that the clearance between the scroll'and the Wheel in the volume 'blower'is much greater than in the pressure blower.

The improvement to which the present invention relates is directed toward combining with the type of scroll used for a volume blower, a restricted space at the point of cut-ofi', so that the blower will handle a large volume of air similar to the ordinary type of volume blower, and will be able to develop an increased pressure, due to an increase in resistance at the outlet to a greater extent than would be obtained with an ordinary blower. In practice, if desired, I may also have this restricted space which controls the point of cut-01f or minimum distance between the housing and the periphery of the wheel, adjustable, so that it may be varied to suit any given conditions under which it is required to operate and give the most eflicientresults for those conditions.

The invention consists in the construction,

combination and arrangement of parts set.

forth in and falling within the scope of the appended claims.

In the accompanying drawings wherein I have shown a preferred embodiment of my invention, Figure l is a vertical sectional view taken through a blower embodying my improvements; the dotted lines showing the scroll of the ordinary pressure blower, and the full lines of the housing illustrating and following the course of the ordinary volume scroll as'far as the point A, where it departs from such scroll and is brought inward close to the periphery of the wheel forming a contracted space or throat between the housing and the wheel at the point ofout- 01f; Fig. 2 is a similar view showing the housing or scroll adjustable at the point of cut-off, and this adjustable portion may be clamped in any desired position of adjust.- ment, or its position may be varied and controlled automatically.

One of the aims and purposes of my invention is to provide a blower having the ability to develop pressure in proportion to the resistance at the outlet and at the same time possess the advantageous features of simplicity, economy of operation and capacity of the centrifugal volume blower. It accomplishes these results to a greater extent than the ordinary centrifugal fan blower and, within the limits in which it is intended to be used, as, for example, for furnace work, it approaches the results obtained by a displacement blower. In the latter the volume of air supply varies with the speed, and the pressure at which the air is supplied varies with the resistance.

When my invention is used to supply air to a furnace the speed of the blower will control the volume of air supplied and the rate of combustion, and the pressure at which the air would be supplied would be dependent upon the character of the fire being maintained, and the thickness of the bed of fuel.

Referring now to the accmnpanying drawings in detail, V designates a blower com prising a housing H and a wheel or fan F revolving therein and mounted in any suitable manner. In the full lines shown in Fig. 1, I have'shown the housing form or scroll of a volume blower, which volume scroll extends from the point A to the point A. At the point A it departs from the ordinary scroll of the volume blower and the remainder of its distance, or, as far the point A it approaches the periphery of the fan wheel and reduces the cut-oft space which ordinarily exists in a volume blower. My device thereby partakes of the function and nature of a pressure blower at the throat portion, so that an increase in the 'sistance at the outlet D will develop an increased, pressure similar to that of a regular pressure blower.

In Fig 2 I have shown a construction wherein the wall of the casing or housing, indicated at E, is rendered adjustable by the hinge or pivot P. The horizontal portion E of the movable wall lies above or overlaps the outlet or discharge duct of the .blower and is slidable thereon and may be oi the part i) is such that Mighoui its movement in acciunplishingr intended purpose it in no my restricts rci'luces the area of the outlet ductfrom, -ing, so that the volume of air (lciron! the blmvci' is not attected by he nio enicnE l' said part E. K. is a {governor having connecting rods w, 1: and c movie-it witi the slide 'l, so that the amount o'l' opening, at the throat of the blower may be autmnatieally regulated according to the speed of the blmver.

lilavinggf thus described my invention. what claim is:

1. A fan blower having the proportimis of wheel and form oi. scroll of a volume lilmver, and an adjustable restricted space at the point of cut-otl' relatively less than Ihnt ot' a volume blower and means for auv m:\tically adjusting the area of said re-- stri'ried space in proportion to the speed of revolution of the wheel.

A blower provided with an adjustable throat section. and means for automatically ontrolling; the space between the wheel and the housing at the point of cutoff.

The conibii'iatiou with a blower oi means for automatically contnillingthe spare between the wheel and the. housing at thcnoint of cut-oil.

K :t tan blower having a scroll casing aui'ldinpeller wheel of the form and relative arrangge nentz of a volume blower, the casing; being n'ovided with an exhaust duct tangential to the in'ipeller Wheel, and the pcri 'iheral wall of the scroll casing: nominated to the exhaust at the point of cut-oil being Zion? in any adjustable position by means of 2 il it. will be, seen that the or H10 lip cry the impeller Wheel, said movable pan sing so curved that the general scroll torn-i ditl'crent points to which said movable Wall or the casing may be maintained atso arranged that throughoutits movement the area of the exhaust duct is not varied.

A fan blower having a scroll casing and impeller wheel of the form and relative arrangement of a volume blower, the casing having an exhaust duet tangential to the impeller wheel and a portion of the pe-' ripheral wall of the scroll casing connected to the exhaust. duct at the point of cut-otl being: hingedly connected to the body of the scroll casing and movable toward and away tron'i the periphery of the impeller Wheel.

6. A fan blower having a scroll casing and impeller wheel of the form and relative arrangement of a volume blower, the casing having an exhaustducttangential to the impeller wheel and a portion of the periphe -a] "all of the scroll casing connected to the exhaust duct at the point of cut-0t? being hingcilly connected to the body of the scroll casing and having an extended slidable. portion, and means associated with said slidable portion for adjustably locating said hinged part relative to the periphery of the impeller Wheel.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

EMBURY MCLEAN.

Nitnesscs R. B. CAvAnAon, O-som Ascnnn. 

